Electromagnetic clutch.



No. 799,720. PATENTED SEPT. 19

H. H. CUTLER. BLBCTROMAGNETIG CLUTCH.

I "T NEIL D 2 APP]: 0A I0 E SEPT 2 1902 8 SHEET8 S L No. 799,720.PATENTED SEPT. 19, 1905.

H. H. CUTLER.

ELEUTROMAGNETIG CLUTCH.

T AIPLIGA ION FILED SEPT 22, 1902 3 SHB S 3' Wizwaew UNITED STATESPATENT OFFICE.

ARNOLD MAGNETIC CLUTCH COMPANY, OF MILWAUKEE, WISCONSIN,

A CORPORATION OF WISCONSIN.

ELECTROMAGNETIC CLUTCH.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed September 22, 1902. Serial No. 124,354.

To aZZ whom it may concern.-

Be it known that I, HENRY H. CUTLER, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented a certain new and useful Improvement inElectromagnetic Clutches, of which the following is a full, clear,concise, and exact description, reference be ing had to the accompanyingdrawings, forming a part of this specification.

My invention relates to improvements in clutch apparatus.

One object of my invention is to provide means whereby a magnetic clutchmay be caused to readily release its armature whenever it is desired todisconnect the same from the machinery operated thereby or to stop themachinery, and thus avoid the trouble caused by a failure of the clutch,owing to the residual magnetism thereof, to fail to release theattracted parts. In order to accomplish this result, I provide means forexerting a yielding pressure between the clutch members, tending to movethem out of contact, whereby when the clutch-windings are deenergizedthe members of the clutch are separated. I further provide means forreversing the current through the energizing coil or coils of the clutchat the time it is desired to stop the machinery or to release theclutch, whereby the coil or coils are more quickly deenergized and theresidual magnetism is neutralized.

My invention further contemplates including a resistance in the path ofthis reversed current, whereby the magnetism of the clutchwindings doesnot reverse and build up suddenly, thus giving more time for the membersof the clutch to separate under the influence of the yielding pressureaforesaid.

Another object of the invention is the provision of means whereby apositive protection is afforded in case the travel of the machineryexceeds the normal or desired amount. For this purpose my inventioncontemplates shortcircuiting the retaining-magnet of the rheostat,whereby at such abnormal movement of the mechanism the rheostat-arm isreturned to normal position and all parts are stopped. Further objectsand the means by which they are accomplished will appear from thedetailed description and claims.

My invention is illustrated in the accompanying drawings, in which thesame reference characters designate like parts throughout the severalviews, and in which- Figure 1 shows a motor connected with a planer forthe operation thereof. Fig. 2 shows the arrangement of the gear-wheelsat one end of the counter-shaft. Fig. 3 is a diagram of the circuits andapparatus involved in my invention. Fig. 1 is a longitudinal sectionalview of the clutch employed in my invention. Fig. 5 is an end view ofthe same. Fig. 6 is a sectional view of a modified form of clutch. Fig.7 is a face View of the starting and reversing switches. Fig. 8 is anedge view I thereof, and Fig. 9 is a view of the same at right angles toFig. 8.

In Fig. 1 the numeral 2 represents a planerbed or analogous part, thegear-wheel 3 being connected with a shaft to operate the planer-bed in asuitable manner. A bevelgear meshes with the gear-wheel 3 and is mountedupon a shaft 5, to which is secured a small gear-wheel 6 near one endand a larger gear-wheel 7 at the other.

8 represents a magnetic clutch of special form, which will be describedhereinafter and which operates a pinion 9, meshing with the gear-wheel 7upon the counter-shaft 5, and a similar pinion 10 is operated by theclutch at its opposite end, said pinion, as shown more clearly in Fig.2, engaging with an intermediate gear 11, which intermeshes with thegear-wheel 6 on the shaft 5. The clutchshaft 12 forms a continuation ofthe shaft of the motor 13, whereby when the latter is operated themagnetic clutch 8 may be operated to drive the planer-bed in onedirection at one speed and in the opposite direction at a differentspeed.

The clutch 8 is shown in detail in Figs. 4 and 5, in which the shaft 5is provided with a non-magnetic sleeve 14:, suitably secured thereto bya key 15 and upon which the clutch member or driving member 16 of theclutch is carried, said member being secured by the key 17 to the sleeve1 1. The said member is provided in each of its opposite faces with anannular channel 18, in which a magnet-coil19 is wound, suitable strips20 being placed at intervals outside of the coil 19 across the channel18 and secured to the member 16 by screws 21 21 to hold the coil inplace. Upon the outside of the member the contact-rings 22 22 22 arelocated, said rings being each provided with laterally-extending lugs atsuitable intervals, beneath which and over which suitable insulatingstrips or washers are provided, a screw 24 being passed through the saidstrips and lugs into the member 16 to secure the rings in place,aninsulating-lmshing surrounding the screw 24. The outer terminals of themagnet-coils .19 are connected with the outer rings 22, and the innerterminals are connected to the inner rings. Suitable stationary brushesare provided to connect withthese rings to convey the current thereto,and a reversing-switch, as hereinafter described, is employed in thecircuit to properly direct the current through said coils.

The pinion 10, at the left-hand side of the clutch, rotates upon anon-magnetic sleeve 25, carried by the shaft 5, and is secured, by meansof key 26, to the hub 27, having the radiating arms 28, as shown moreclearly in Fig. 5. Bolts are passed through suitable apertures in theends of these arms and have cylindrical heads 29, projecting from theirinner faces. The armature-disk 30 for the lefthand magnet-coil iscarried upon these circu lar heads, suitable non-magnetic bushings 31being provided in the apertures in the disk, whereby when the magnet isenergized the disk slides forward upon the projections 29 andfrietionally engages the face of the clutch member 16, thus causing thepinion to retate with the clutch and motor. At the opposite end of theclutch a like arrangement exists, the pinion 9 being carried upon asimilar non-magnetic sleeve 25, secured by key 526 to the hub of thearms 28. A similar armature-disk is provided for the right-hand coil 19of the clutch.

Pins 32 extend through member 16 and project slightly beyond the face ofthe same, whereby when one-of the disks is attracted it strikes the endsof the pins 32 and releases by the impact the opposite armature in casethe latter has just been attracted. This arrangement thus insures thereleasing of one armature before the other is engaged with the member16, whereby strain and injury to the mechanism due to the sticking of anarmature by the residual magnetism are avoided.

In order to push the armature-disk out of contact with the faces of theclutch member 16 when it is desired to stop the mechanism, spring-pins33 and 34'are provided near the hub of the'member 16, a coiled spring 35serving to press these pins outwardly,whereby when the magnet-coils aredeprived of operating-current the pins push the armaturedisks away fromthe face of the magnet.

As stated above and as shown in Fig. 3, a suitable reversing-switch 37is necessary, which switch is preferably actuated by the planer. Thisswitch is shown in Figs. 7, 8, and 9, in which 37 indicates theinsulating base upon which the operating parts are mounted, 38 being thesecuring lugs or feet, by means of which the same may be secured to thewall, floor, or other support.

39 is the starting and stoppingswitch, which is adapted when moved bythe handle 39 to one limit of its movement until checked by the stop 40to engage the stationary contacts 41, 42, 43, and 44 and at the oppositelimit of its movement to engage contacts 45, 46, 47, 48, and 49,21suitable stop serving to prevent the lever moving beyond operatingposition in this direction. Suitable brushes, preferably of the carbontype, are carried by the switch 39, said brushes being indicated at 51,52, 53, 54, and 55, these brushes being vertically adjustable, as shownin Fig. 8. The reversing-switch 56 is mounted near one edge of theinsulating-base 37 and is provided with a pair of brushes 57 and 58,which engage in the normal movement of the lever 56 the stationarycontacts 60 and 61 and at the opposite limits of its normal movementslike contacts 62 and 63. Other contacts 64 and 65 and 66 and 67 may beengaged by the lever if swung to an abnormal distance to either side. Atthe opposite end of the lever a slot 68 is provided in which areciprocatingbar operated from the planer-bed is secured by means of thebolt 69, the slot permitting a certain amount of adjustment.

In the diagram in Fig. 3 the starting-rheostat is shown at 70, 71 beingthe usual retaining-magnet for the arm of the rheostat, 72 being aswitch which is normally opened by a projection upon the rheostat-arm.The two coils of the clutch 8 are shown at 19, and the reversing-switchis shown at the upper side of the insulating-base 37. 73 indicates aresistance adapted to be placed in series with the magnet-coils 19 whenit is desired to stop the mechanism. A solenoid-brake 74 is adapted tobe applied to the motor when its solenoid is deenergized, themotor-arimiture being indicated at 75 and its shunt-field at 76 and theleads of the power-circuit at 77 and 78.

In the operation of the apparatus the switch 38 is moved to startingposition and the arm of the rheostat is moved toward the right. As soonas the arm of the rheostat reaches the first contact of the rheostatresistance 79 a circuit is completed from the negative side of thepower-circuit through the armature of the motor, thence over conductor80 and through the resistance 79, the arm of the rhethrough the arm ofthe rheostat and over conductor 81 to the opposite side of the circuit.The motor-armature and its field are thus energized and the motor isstarted. The res1stance' in the armature-circuit is gradually cut LIIout as the arm of the rheostat is moved to the right, and the resistance79 is cut into the shunt-field to reduce its strength as the armproceeds in itstravel; The starting-lever 38 having been placed instarting position, a path for current through the brake is provided fromthe negative side of the power-circuit over conductors 84 and 85 tocontact 48, thence through the switch 38 to contact 49, over conductor86 to the solenoid of the brake. It then passes by way of conductor 87to the switch 72 upon the base of the rheostat 70 and through conductor88 to conductor 81 and the other side of the power circuit, the switch72 having been closed as soon as the arm of the rheostat is moved fromnormal position. The brake-solenoid is thus energized and the brakeprevented from stopping the mechanism. A path for current through one ofthe coils of the clutch is also provided, said path being traced fromthe negative side of the power-circuitthrough conductors 84 and 85,thence through the switch 38 to contact 47, and thence over conductor 89to point 22, which corresponds to the central contact-ring upon theclutch,and thence through the lefthand winding 19 of the clutch-magnet,over conductor 90, to the contact 61 of the reversing-switch. Thereversingswitch 56 being assumed to be in the position shown, at thistime circuit is completed therethrough to the contact 60, which isconnected by conductor 91 with the contact 45 of the starting-switch.Thecircuitisthen completed through switch 38 to the contact 46 andthence over conductors 92 and 93 to the opposite side of thepower-circuit. The left-hand magnetcoil 19 is thus energized and thecorresponding armature-disk is attracted, which operates the planer inthe corresponding direction. As the planer-bed reaches the limit of itsdesired movement the reversing switch is brought into contact with thecontacts 62 and 63, whereby current is cut off from the lefthand coil 19and is directed through the corresponding right-hand coil, which isconnected, by means of conductor 94, with the contact 63, circuit thenbeing completed through the reversing-lever to the contact 60, fromwhence the path is the same to the other side of the circuit as justtraced. As long as the apparatus remains in this condition the planerwill continue to be operated automatically by means of thereversing-switch 56, which is, as stated before, operated from thereciprocating mechanism of the planer, (indicated by the rod in dottedlines in Fig. 3.)

Should current upon the line fail for any length of time, theretaining-magnet 71 will be deenergized and the spring upon the rheostatwill cause it to return to normal position, thus opening the circuits ofthe apparatus, as well as switch 72, and deenergizing the solenoid ofthe brake, thus stopping all parts. In case the reciprocating mechanismof the 1 switch 56 should fail to stop at the proper point in itsmovement the lever 56 will be moved into contact with either thecontacts 64 and upon one side or the like contacts 66 and 67 upon theother, in either of which cases the retaining magnet 71 would be shuntedby the conductors 95 and 96, leading from opposite sides of theretaining-magnet to the said contacts 64, 65, 66, and 67. hen thisoccurs, therefore, all parts are to be restored to normal position andthe machinery stopped, as above described.

hen the operator desires to stop the mechanism, the starting-lever 38 ismoved to the stopping position, with a result that the circuit is openedbetween the contact 49 and the switch 38, thus permitting the brake tobe immediately applied. Moreover, the current is reversed through thecoil of the clutchmagnet. This circuit may be traced from the negativeside of the power-circuit through conductor 84 to contact 44, thencethrough the switch 38 to contact 43, then through the resistance-coil 73to contact 45, thence over conductor 91, through contact 60, thereversing-lever 56 to contact 61, and thence over conductor 90 andthrough the coil 19 in the reverse direction from that above described,when the parts are in the same position, but with normal running, thenceto point 22 and over conductor 89 to contact 42,thence through theswitch 38 to contact 41 and over conductors 97 and 93 to the oppositeside of the power-circuit. The current in this path therefore serves todeenergize the operating-magnet of the clutch. This part also includesthe resistance 73, so that a large enough current does not flowtherethrough to so quickly build up the ma netism of the clutch in theopposite direction that its armature will not be released by thespring-pins 33 or 34. The starting-lever may now be moved to anintermediate position, in which the circuits through the clutch-coilsare opened.

In Fig. 6 I show a modification of the clutch in which only onearmature-disk is employed. the spring-pins 34 serving to press the saidarmature away from the face of the driving member when the magnetism ofthe coil in the latter is reversed by the arrangement shown in thediagram and when the resistance 73 is included in series therewith.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is-

1. A clutch having a magnet member and an armature member, of means forreversing the current through the coil or coils of said magnet memberwhen it is desired to deepergize the same, means for resilientlypressing said armature member away from said magnet member, whereby thearmature is freed from the magnet when the latter is deenergized,substantially as described.

2. A clutch having a magnet member and an armature member, said armaturehaving an outward yielding pressure exerted against the same, of meansfor reversing current through the former when it is desired todeenergize the same, and means for including a resistance in the path ofsaid reversing-current, substantially as described.

3. A clutch having two members, of means for exerting a yieldingpressure between said members to force them apart when deenergized,andmeans for reversing current through the winding or windings of saidclutch when it is desired to denergize the same, substantially asdescribed.

4:- A clutch having a magnet member and an armature member, means torelease said armature member from the magnet member by impact, and meansfor yieldingly pressing said armature away from the magnet member,substantially as described.

5. A clutch having a magnet member, an armature member opposite eachface of said magnet member, means for yieldingly pressing said armaturemembers away from the sition, and means for short-circuiting said retaining-magnet when the reversing-switch exceeds its normal travel,substantially as described.

7. The combination with a motor, ofa clutch to connect the same withmachinery to be driven, means for reversing the connection in saidclutch to drive the machinery in different directions, and means toreverse current through the coils of said clutch when it is desired tostop the same,-substantially as described.

8. The combination with a motor, of a clutch to connect the same withmachinery to be driven, means for reversing the connection in saidclutch to drive the machinery in diflerent directions, means to reversecurrent through the operating-coil of said clutch and to cut in aresistance in series therewith when it is desired to stop the machinery,substantially as described.

9. The combination with a motor, of a magnet-clutch to connect the samewith the machinery to be driven, said clutch having anarmatureyieldingly pressed away from the same, and means for reversing thecurrent through the actuating-winding of said clutch and for including aresistance inseries therewith when' it is desired to stop the machinery,substantially as described.

In witness whereof I have hereunto subscribed my name in the presence oftwo witnesses.

HENRY H. CUTLER. WVitnesses:

A. W. BERRESFORD, F. L. PIERCE.

